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Immune System

The immune system is a network of cells, tissues, and organs that work together to protect the body from infection. The human body provides an ideal environment for many microbes, such as viruses, bacteria, fungi, and parasites, and the immune system prevents and limits their entry and growth to maintain optimal health.

Understanding the Immune System

Research

This animation shows how the body naturally responds to and destroys invading bacteria.

Although scientists have learned much about the immune system, they continue to study how the body targets invading microbes, infected cells, and tumors while ignoring healthy tissues. New technologies for identifying individual immune cells help scientists determine which cells trigger an immune response under various circumstances. Improvements in microscopy also allow for observations of living immune cells as they interact within lymph nodes and other body tissues.

In addition, scientists are rapidly unraveling the genetic blueprints that direct the human immune response, as well as those that dictate the biology of viruses, bacteria, fungi, and parasites. The combination of new technology and expanded genetic information promises to reveal more about how the body protects itself from disease. In turn, scientists can use this information to develop new strategies for the prevention and treatment of infectious and immune-mediated diseases.